The invention relates to a double-flow butterfly valve part. Butterfly valve parts are known, for example from such disclosures as EP-B No. 0012598. When the gas pedal is activated in this known valve part, it is intended that a gradual and readily controllable increase in power of an internal combustion engine is achieved. This is of advantage especially in the case of high-performance internal combustion engines for driving motor vehicles to prevent the driving wheels spinning when starting off and to make sensitive reversing possible. In the known butterfly valves parts, the two butterfly valves are closed by the action of their own springs. Consequently, when the gas pedal is depressed, at first the force of the spring for the first butterfly valve must be overcome and, after the pedal has traversed a certain path, the force of the spring for the second butterfly valve must be overcome additionally, as a result of which the force exerted on the pedal must be increased suddenly. When allowing the gas pedal to retract, the two butterfly valves are closed consecutively by their springs. Corresponding to the coupling between the two butterfly valves, the second butterfly valve is normally closed first after a pedal path of about 40%. As the pedal is allowed to retract further up to its final position, that is, after a further 60% of pedal path, the first butterfly valve reaches its closing position. Should the spring of the second butterfly valve break, the second butterfly valve, as the gas pedal is allowed to retract, is moved in the closing direction by the spring of the first butterfly valve over the rod linkage, however only after a free play of about 10.degree. and then synchronously with the first butterfly valve. If the spring breaks, it will be apparent that the second butterfly valve will reach its end position together with the first butterfly valve, so that the response and operational behavior of the internal combustion engine falls off appreciably in quality compared to the normal state.